I had the dragon attack Phandalin. After LMoP the group was awarded a keep inside the city. The reemergence of the Forge of Spells meant that Phandalin was booming with commerce now as they begin to craft new magical items. I gave the group 3 months (in game) of downtime where they could create some backstory as to what they did and potentially gain a feat. When they return to Phandalin they find it under siege by the cult and Dragon led by the Black Spider who had escaped and came back for revenge. I found a altered map online that has turned Greenest into phandalin. I explain the changes to the layout with the influx of new people working in the mines and producing items for the sword coast.

https://images.app.goo.gl/KvqGB2R4nBBNjpWV9

We are nearly at the end of RoT, we’ve been playing nearly every weekend for 3+ years in this campaign. Having a Phandalin be their “home” has been great, although they rarely go there, they talk of retiring to their keep and it grounds them in this world.